Polyesters from 1,4-dialkyl-1,4-cyclo-hexane-dicarboxylic acid and or-ganic diols

ABSTRACT

POLYESTERS FROM 1,4-DIALKYL-1,4-CYCLOHEXANE DICARBOXYLIC ACID AND ORGANIC DIOLS. SYNTHESIS OF THE DICARBOXYLIC ACID FROM SUBSTITUTED BUTADIENE AND ACRYLIC COMPOUND STARTING MATERIALS IS DISCLOSED. ADVANTAGES OF A VARIETY OF POLYESTERS ARE ILLUSTRATED.

"United States Patent 3,776,886 POLYESTERS FROM 1,4-DIALKYL-1,4-CYCLO- I-mXANE-DICOXYLIC ACID AND OR- GANIC DIOLS Ralph C. Schreyer, Wilmington, Del., assignor to E. I. du Pont de Nemours and Company, Wilmington, Del. No Drawing. Application Nov. 4, 1971, Ser. No. 195,858,

now Patent No. 3,725,343, which is a division of application Ser. No. 722,204, Apr. 18, 1968, now Patent No. 3,646,223. Divided and this application Dec. 20, 1972, Ser. No. 316,745

Int. Cl. (308g 17/08 US. Cl. 260-47 C 4 Claims ABSTRACT OF THE DISCLOSURE Polyesters from 1,4-dialkyl-1,4-cyclohexane dicarboxylic acid and organic diols. Synthesis of the dicarboxylic acid from substituted butadiene and acrylic compound starting materials is disclosed. Advantages of a variety of polyesters are illustrated.

REFERENCE TO RELATED APPLICATION This is a division of application Ser. No. 195,858, filed Nov. 4, 1971, now US. Pat. No. 3,725,343, as a division of application Ser. No. 722,204, filed Apr. 18, 1968, now US. Pat. No. 3,646,223.

BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The instant invention provides compounds of the general formula:

wherein R and R are selected from --CO X, -CONX --COC1, --CH NH -CN, and CH OH, X being the same or different and independently selected from hydrogen and alkyl radicals of from 1 to 6 carbon atoms; and R and R are independently selected from alkyl radicals of 1-4 carbon atoms.

This invention also provides a process for the preparation of these compounds which comprises contacting a compound of the general formula:

Ra CO R5 with carbon monoxide in the presence of an acid catalyst, wherein R is selected from hydrogen and alkyl radicals of from 1-4 carbon atoms, and R and R are as defined above.

3,776,886 Patented Dec. 4, 1973 'ice This invention further provides polymers characterized by the presence in the molecular chain of the recurring structural unit:

wherein P and Q are selected from DESCRIPTION OF THE PREFERRED EMBODIMENTS wherein R is as defined above, with an acrylic compound of the general formula wherein R and R are as defined above in the presence of a solvent at elevated temperatures. Such butadienes can include, for example, isoprene; 2-ethyl-1,3-butadiene; 2-propyl-l,3-butadiene and 2-t-butyl-l,3-butadiene; and the acrylic compounds can include, for example, methacrylic acid, ethyl acrylic acid, propyl acrylic acid, butyl acrylic acid, methyl methacrylate, ethyl methacrylate, and methyl ethacrylate.

The molar ratio of the butadiene to acrylic compound is not critical and can vary from about 10:1 to about 1:10. Approximately stoichiometric ratios are preferred for reasons of economy and ease of recovery of the products. The temperature employed in the reaction of the butadiene with the acrylic compound is generally about from to 300 C., and preferably about from to 200 C. The pressure is not critical to the reaction. However, a moderately elevated nitrogen atmosphere is preferred, e.g., of about from 50 to 1000 psi. Contact time for the reaction can vary from about 15 minutes to 24 hours, but the reaction is usually substantially complete in about from 2 to 4 hours.

This reaction proceeds satisfactorily without a catalyst, however, particularly in the case of methyl methacrylate, the use of a Friedel-Crafts catalyst is found to promote a favorable distribution of the 4- and 3- alkyl-3-cyclohexene-l-carboxylate isomers, and the use of such catalyst is therefore preferred. Such catalysts can include, for example, aluminum chloride, ethyl aluminum dichloride, diethyl aluminum chloride, boron trifiuoride, and titanium tetrachloride. In the presence of catalytic amounts of aluminum chloride, about 95% of the recovered product is the desired 4-isomer compared to a 70:30 distribution of the 4- to 3-isomers in the absence of a catalyst.

Alternatively, the 1,4-dialkyl-3-cyclohexenecarboxylic acid starting material can be prepared, for example, by hydrolysis of the adduct formed by reaction of isoprene and methacrylonitrile as well as the selective oxidation of the adduct formed in the reaction between isoprene and methacrolein.

The carbonylation of the starting material is carried out by contacting the 1,4-dialkyl-3-cyclohexenecarboxylic acid or alkyl 1,4-dialkyl-3-cyclohexenecarboxylate, with carbon monoxide and an acidic catalyst. The carbon monoxide can be supplied, for example, as carbon monoxide gas or as a compound which yields carbon monoxide in the acidic solution, such as formic acid and oxalic acid. The acidic catalyst can be selected, for example, from strong mineral acids, for example, those having a pH of 1, such as sulfuric acid, at least 90% concentrated, HF or mixtures of hydrofluoric acid and boron trifiuoride. A combination of carbon monoxide gas and 96% sulfuric acid has been found to result in especially high yields and conversions. At least about moles of acid per mole of reactant should be present to obtain good yields and as many as 15 to 20 moles of acid per mole of reactant can be used.

The temperature for the carbonylation is not critical and usually varies about from 0 to 100 C. However, temperatures of about from 20 to 50 C. have been found particularly effective. The pressure is also not critical to the process of the instant invention, and can be any pressure convenient for use with the particular source of carbon monoxide. For example, the pressure can be autogenous when using formic acid or up to about 20,000 p.s.i. when employing carbon monoxide gas. The lowest pressure that will give optimum yields is generally employed for convenience and economy.

The reaction time for the carbonylation varies from about 30 minutes to about 4 hours, depending on the particular reactants and carbonylation conditions; generally, the reaction is complete in 1 to 2 hours.

The resulting 1,4-dialkyl-1,4-cyclohexane diacid or diester can be readily converted to the other derivatives. The corresponding dialkyl ester can be prepared from the diacid by treating the diacid with a lower alkanol, e.g., having 1-8 carbon atoms, such as methanol, ethanol, butanol, and isopropanol, in the presence of a strong mineral acid, for example, sulfuric acid. The corresponding glycols, cis, and trans-1,4-dialkyl-l,4-bis(hydroxymethyl)cyclohexane, can be prepared by hydrogenation of the dialkyl ester using a metal hydride or copper chromite catalyst. The corresponding acid halide, 1,4-dialkyl- 1,4-cyclohexane-dicarbonyl halide, is obtained by contacting the diacid with a thionyl halide, such as thionyl chloride or thionyl bromide. The diamine, 1,4-dialkyl-1,4- cyclohexanedicarboxamide, is obtained by contacting the diester or the acid halide with ammonia. This can be effected, for example, by placing the diester in solution, e.g., with an ether or alcohol, and passing ammonia gas through the solution. Alternatively, the diester can be contacted with an aqueous solution of ammonium hydroxide, having a concentration, for example, of about from to 30% ammonium hydroxide.

The diamide can be dehydrated to form the corresponding dinitrile. Suitable dehydrating agents can include, for example, thionyl halides such as thionyl chloride or thionyl bromide, phosphorous oxychloride, pyrophosphate and acetyl chloride. The dehydration can also be accomplished with heat and a solid catalyst such as alumina.

The dinitrile can be hydrogenated at ambient temperature to the corresponding diamine by contacting it with hydrogen in the presence of a catalyst. Catalysts which have been found especially effective include the noble metal catalysts, e.g., platinum, palladium, and rhodium, Raney nickel catalysts and rhodium-on-nickel catalysts. Solvents for this hydrogenation can include, for example, alcohols of from 1-4 carbon atoms, such as methanol and ethanol, chlorinated hydrocarbons such as methylene chloride, and ethers such as isopropyl ether, n-butyl ether, and ethyl ether.

The condensation polymers of the instant invention are derived from 1,4-dimethyl-1,4-cyclohexanedicarboxylic '4 acid and are characterized by the presence in the molecular chain of the diradical Ra P- wherein R R, P, and Q are as defined hereinbefore. Polymers in which units of the above diradical are joined by recurring ester and amide groups are found to have especially desirable properties.

Generally, the polymers of the instant invention should have a degree of polymerization of about from 15 to 150, and preferably 20 to 150.

The polyesters of the instant invention comprise solid linear condensation polymers of a dicarboxylic acid and a diol as basic molecular units wherein at least one of said units contains a six-membered cycloaliphatic ring with carboxyl or methyleneoxy groups attached in 1-4 relationship to ring carbon atoms, which ring carbon atoms are also attached to alkyl groups. Any additional constituent of the diol or acid is generally selected from ether oxygen and saturated hydrocarbon groups having a total of up to 8 carbon atoms. The polyester can be composed of a dicarboxylic acid and at least one bifunctional compound reactive with dicarboxylic acids to form linear condensation polymers, at least 50 mole percent of said bifunctional compound consisting of a diol in which two hydroxymethyl groups are attached in 1-4 relationship to a six-membered cycloaliphatic ring, with the point of attachment being a ring carbon atom which is also attached to an alkyl group. The remainder of the bifunctional component may be another dihydroxy compound, a diamine, a diisocyanate, a hydroxy acid, a hydroxy amine, or an amino acid. In another embodiment of the invention the polyester may be composed of a diol and at least one bifunctional compound reactive with diols to form linear condensation polymers, at least 50 mole percent of said bifunctional compound consisting of a dicarboxylic acid containing at least one G-membered cycloaliphatic ring with the two carboxyl groups attached in 14 relationship to ring carbons which are also attached to alkyl groups. The remainder of the bifunctional component may be another dicarboxylic acid, a hydroxy acid, a. diisocyanate, or an amino acid.

A preferred embodiment of the invention comprises polyesters characterized by possessing recurring units of one of the following formulas:

where G is a divalent organic radical obtained by removmg the hydroxyl groups from the organic diol G(OH) and may be aromatic, aliphatic or cycloaliphatic, A is a divalent organic radical obtained by removing the carboxyl groups from the organic dicarboxylic acid A(COOH) and is preferably an aromatic radical, and R is a lower alkyl radical having one to four carbon atoms.

The starting material dicarboxylic acids from which the polyesters are prepared may be in the form of their ester-forming derivatives, i.e., their carbonylhalides, anhydrides, salts, or esters, particularly their esters with the lower aliphatic alcohols or with phenol. Terephthalic acid and 1,2-bis (4-carboxyphenyl)ethane are examples of dicarboxylic acids A(COOH) which may be used with the novel diols to form polyesters, and these acids are indeed particularly preferred for the purpose of producing polyesters suitable for spinning textile filaments. Other examples of suitable acids include bibenzoic acid, bis-4- carboxyphenylsulfoxide, bis-4-carboxyphenylether, 1,2-bis (4-carboxyphenoxy)ethane, naphthalene-2,6-dicarboxylic acid, 1,4-bis(4 carboxyphenoxy)butane, 1,4-bicyclo [2.2.2]octanedicarboxylic acid, hexahydroterephthalic acid, and bis(4-carboxyphenoxy)-p-xylene. The divalent radical A is preferably composed primarily of carbon and hydrogen but may contain, in addition to the two carboxyl groups other non-hydrocarbon components or substituents which are inert in the polyesterification reaction. Mixtures of the dicarboxylic acids may be employed.

Organic diols G(OH) suitable for reaction with the novel acids of the invention to form useful polyesters are preferably chosen from the bis(hydroxymethylcyclohexyl)a1kanes or bis(hydroxymethylcyclohexyl). Other suitable diols which may be employed include ethylene glycol, propylene glycol, butylene glycol, 2,2-dimethylpropylene, glycol, 2,2,3,3,4,4-hexafluoro 1,5-pentanediol, hexamethylene glycol, decamethylene glycol, diethylene glycol, ethylene-dioxydiglycol, cis or trans hexahydro-pxylylene glycol, cis or trans-quinitol, 1,4-bis(hydroxymeth'- ylcyclohexyl cyclohexane, 1,4-bis 3-hydroxypropyl benzene, 2,6-bis(Z-hydroxyethyl)naphthalene, 1,4-bis(2-hydroxyethoxy)benzene, hydroquinone, 4,4-dihydroxybiphenyl, 2,2-bis(4-hydroxyphenyl) propane, bis(4-hydroxyphenyl)propane, bis(4-hydroxyphenyl)methane, 1,l-bis (4-hydroxyphenyl)ethane, and 1,2-bis(4-hydroxyphenoxy)ethane. Mixtures of diols may be used.

A convenient method for preparing the polymers involves reaction of an alkyl ester of a suitable dicarboxylic acid with a suitable organic diol in an ester interchange reaction followed by polycondensation at high temperature and at low partial pressure of the diol, until a polymer of the desired molecular weight is produced. It is desirable to employ an ester of the dicarboxylic acid formed from an alcohol or a phenol with a boiling point considerably below that of the organic diol so that the former can be removed easily from the reaction zone by distillation. It is preferred to use the methyl or ethyl esters. The ester interchange reaction is advantageously carried out in the presence of ester interchange catalysts such as manganous acetate, calcium acetate, sodium methoxide, sodium hydrogen hexabutoxytitanate, tetraalkyltitanates such as tetraisopropyltitanate, or other suitable ester interchange catalysts as described in the literature relating to preparation of polyesters.

Following the ester interchange reaction, heating is continued under reduced pressure until the excess diol is removed and the polymerization reaction has proceeded to the desired degree. The final stages of polymerization may be carried out with the polymer in the molten state or, if desired, the reaction may be completed by solid-phase polymerization. The polymerization reaction may be carried out in the presence of catalysts such as antimony trioxide, litharge, zinc acetate, or other suitable polycondensation catalyst as described in the literature.

Sodium hydrogen hexabutoxytitanate and the tetraalkyl titanates such as tetraisopropylenetitanate are examples of catalysts which may be used for both the ester interchange and polymerization steps.

When the polymer is to be prepared from a dihydric phenol it is suitable to first react the dihydric phenol with acetic anhydride and then use the resulting dihydric phenol diacetate as the starting material for reaction with a suitable dicarboxylic acid. The initial reaction is advantageously carried out in the presence of a catalyst such as sodium acetate.

Homopolyesters having Formula I or II as described above are generally crystalline, high melting and stable to heat and light. Accordingly, they are well suited to the formation of fibers, films and other useful shaped articles prepared by molding and extrusion techniques.

as c approaches 0, where (r) is the relative viscosity, and c is the concentration in grams per 100 ml. of solution. The relative viscosity (r) is the ratio of the viscosity of a solution of the ploymer in a suitable solvent to the viscosity of the solvent, per se, measured in the same units at C. Intrinsic viscosity is a measure of the degree of polymerization.

For the polyesters in the examples, suitable solvents include a mixture of phenol and 2,4,6-trichlorophenol in a 10/7 by weight ratio, a mixture of trifluoroacetic acid and methylene chloride in a 1/3 by volume ratio, and sulfuric acid.

Additional polymers of the instant invention can be prepared from the novel monomeric compounds of the instant invention by conventional techniques for the formation of condensation polymers. For example, polyamides, polyureas, and polyurethanes can be prepared according to the general reaction procedures set forth in Sorenson and Campbell, Preparative Methods of Polymer Chemistry, New York (1961) on pp. 60, 92 and 105, respectively.

In the following examples, which further illustrate the instant invention, parts and percentages are by weight, unless otherwise indicated.

EXAMPLE 1 1,4-dimethyl-l,4-cyclohexanedicarboxylic acid Part A.-A mixture of 52 parts of methacrylic acid and 85 parts of isoprene is heated in a stirred stainless steel autoclave at C. and under 1000 p.s.i. nitrogen pressure for 2 hours. Distillation of the discharged product under 1 2 mm. vacuum gives 8.5 parts of a fraction 1 B.P. 60-100" C., and 53.5 parts of a fraction II, B.P. l051l 0 C., which solidify on cooling in Dry Ice. Fraction II recrystallized from n-heptane gives 35 parts of 1,4-dimethyl-3-cyclohexenecarboxylic acid, M.P. 60-6l C. (literature value 6263 C.), in 98% purity. Purity is determined, after converting the acid to the lactone with sulfuric acid, by vapor-phase chromatographic (VPC) analysis using a 5 ft. FFAP column (Wilkens Instrument and Research Inc.). Fraction I was identified as the 1,3- dimethyl isomer.

Part B.--A charge of 25 parts of the adduct, 1,4- dimethyl-3-cyclohexenecarboxylic acid and 230 parts of 96% H 80 which had been cooled to 0 C., is stirred in a glass liner at 35 C. and placed in a stainless steel autoclave under 15,000 p.s.i. carbon monoxide pressure for 2 hours. The pressure in the autoclave is thenvented and the reaction product poured over 500 parts of ice. A water-insoluble product, identified as the trans-isomer, is filtered off and the water-soluble cis isomer is recovered by cooling the remaining filtrate to l0 C. and filtering to remove the solid acid. After a twofold extraction with methylene chloride, 31.6 parts of both isomers, about 60% (23.9 parts) trans-1,4-dimethylcyclohexane-1,4-dicarboxylic acid, M.P. 308 C., and about 40% (7.7 parts) cis 1,4 dimethylcyclohexane-l,4-dicarboxylic acid, M.P. 188-l89 C., is obtained, giving a 99% conversion and a 97.3% yield. The structures of the products are confirmed by NMR and IR analysis.

Analysis.Calcd. for C H O (percent): C, 60.00; H, 8.00. Found, trans-C (percent): C, 60.46, 60.46; H, 7.73, 7.90. Found, cis-C (percent): C, 59.02, 59.23; H, 7.90, 7.88.

If Part B of Example 1 is repeated, using 1,4-diethyl-3- cyclohexene-carboxylic acid or 1-methyl-4-propyl-3-cyclohexene-carboxylic acid instead of 1,4-dimethyl-3-cyclohexene-carboxylic acid, the products obtained will be, respectively, 1,4-diethyleyclohexane 1,4 dicarboxylic acid 8 per chromite catalyst and 400 parts of absolute methanol is hydrogenated at 10,000 p.s.i.g. and 225 C. for 12 hours. Upon completion of the reaction, the catalyst is removed by filtration and after evaporation of the methanol, 60 parts (94% conversion) of a white, crystalline and 1-methyl-4-propyl-cyclohexane-1,4-dicarboxylic acid. solid is recovered. The solid is identified as a mixture of a) e-.00:- 2.21 7. 8.2.131 .fttihhialfialih In Examples 2-6, 1,4-dimethyl-3-cyclohexenecarboxylic l h acid is treated with concentrated H 80 under varying EXAMPLE 10 carbonylation conditions as indicated in the following table to give l,4-dimethylcyclohexane-1,4-dicarboxylic C1s'14'd1methy1'14'bls(hydroxymethyl)cyclohexane acid in the yields indicated. A mixture of 10 parts of pure cis-1,4-dimethyl-1,4-

TABLE I GO Solid dibasic acid 2 ressure Time Temp. Solid Liquid Example Adduct H1804 p.s.i.g.) (hr.) 0.) acid (laetone) 3 Conversion Yield 1 1,4-di1nethyl-3-cyclohexenecarboxylic acid. 1,4-dimethyl-l,4-eyclohexanediearboxyli0 acid. 1,4-dimethyl-2-oxabi0yclo[2.2,2]00tan-3-0ne.

EXAMPLE 7 bis(carbomethoxy)cyclohexane, 15 parts of barium-prop parts f isoprene, 100 pal-ts of h l 25 moted copper chromite catalyst, and 100 parts of absolute methacrylate, and 7 parts of aluminum chloride are mixed ethanol 15 hydfogehated at 10,000 P- a 150 C. for in 175 parts of benzene The resultant reaction is 24 hours 1n a stainless steel autoclave. The discharged thermic and no external heat is applied. The temperature Product 13 filtered from the ye and the ethanol preaches the reflux temperature of isoprene (34 C.) and mated 9 Sfeam cohe- A P 2 f the p h after four hours reaction time, the resulting mixture is P 18 dlstllled through all 18 VlgfellX f g two poured into water. Two layers form and are separated. frachons; Fractlell 1, Pf of a seml-eohd, The organic layer is dried over anhydrous magnesium 5 and fraetleh Parts f a Selld, sulfate. Benzene is removed by evaporation and subse- 5 Fraeheh 2 lecfeefystalhled jfl quent distillation at 0.9 mm. Hg pressure and 53-60 c. e fi glve pa M.P. 124-131 C. The product 1s gives 153 parts (-90% yield) of the intermediate adduct ldemlfied as 1,4 Y -lr Y Y Y y oin a 9/1 ratio of methyl 1,4- and methyl 1,3-dimethyl-3- hexane y elemental analysecyclohexenficarboxylam Analyszs.Calcd. for C H O (percent): C, 69.76; Part B.10 parts of the product of Part A and 183 H, Found 6962, 1 parts of concentrated sulfuric acid are heated to 70 C. and maintained at that temperature for two hours under VPC analyels 0f the dlaeefate ester lfldleated 12,000 p.s.i.g. carbon monoxide. 7.8 parts (-65% yield) content of the desired acid, 1,4-dimethyl-cyclohexane-1,4-dicar- EXAMPLE 11 hoxyhc 391d obtamed' Trans-1,4-dimethyl-1,4-bis(hydroxymethyl) EXAMPLE 8 cyclohexane 4-b bo- C18 and fig i g fiig gig Meat A mixture of 30 parts of barium-promoted copper chromite catalyst, 15 parts pure trans-1,4-dimethyl-1,4-bis 100 parts of 1, -d y Y f (carbomethoxy)cyclohexane, and 133 parts of absolute acid is added to 790 Parts of 95% methanol a m ethanol is hydrogenated at 10 000 p si for 24 hours at bottom flask, foll wed y addition of 92 Parts of 96% 5o 230 C. The discharged product is filtered to remove the H The reactio miXtllle is heated to reflux (69-710 catalyst and the solvent removed on a steam cone 'vin C.) for 2 hours, then allowed to cool to room temperature 125 parts of solid material A portion of the i and discharged into 2000 parts of distilled water. 101 parts (23 parts) is heated in 214 parts ether and filtered The of solid material precipitates. The solid is removed by undissolved portion (073 part) melts at 15 C filtration and the filtrate is then extracted twice with The rodu t tfi d 14 h 11 h methylene chloride. The methylene chloride extract is g g l g s g i gg g 1S( ydmxy' dried over anhydrous magnesium sulfate and flash cvap- Analysis' calcd for C H o (perce'nt). C 69 orated. 16.7 parts of solid product are obtained after H, Found (penalty; g 63 69 evaporation. The combined products (117.8 parts) are 1150 zsgullncggtlsllegt s g i3g i gllgjlj n g \iPCi analysis of the product indicated 98% trans 1 o con en a white solid, trans-1,4-dimethyl-1,4-b1s(carbomethoxy) EXAMPLE 12 cyclohexane, M.P. 98-99" C., and at B.P. 135.3-136.5/5 mm., 42.3 parts of a colorless liquid, cis-1,4-dimethyll,4 dhnethylcyclohexane l,4 dicarbonyl chloride 1,4-bis(carbomethoxy)cyclohexane. Compound struc- 5 due are Confirmed y infrared p h The P y of A mixture of 13.6 parts of about 85% transand about the1 cs 'gg-lk i t Yt g 13 h i FFAP 153%40cis-1i4-dignggil-1,4-cyclolaexanegicag'boxylic acid co umn 1 ens ns rumen an esearc nc. an par 5 0 2 i Stine at 7 o f 1 y for 12 20 4 (P C, 5316; hours. The excess SOCl is removed by distillation and H, 8.77. Found (percent): C, 62.42, 62.59; H, 8.74, 8.83. further distillation under vacuum gives 1.6 parts of a solid, B.P. 120-140 C./ 10-12 mm. The solid, after re- EXAMPLE 9 crystallization from petroleum ether, yields 0.8 part, M.P. l Y Y Y y IDS-110 C. Further recrystallization gives a solid, M.P. A mixture of 84.5 parts of l,4-dimethyl-1,4-dicarbo- 113-114 C. An additional 7 parts of solid, M.P. 105- methoxycyclohexane, 84.5 parts of barium-promoted cop- -s are Obtained y Washing the column 1 With ether. The product is identified as 1,4-dimethylcyclohexane-1,4-dicarbonyl chloride -by elemental analysis.

Analysis.-Calcd. for C H O Cl (percent): C, 50.63; H, 5.91; Cl, 29.95. Found (percent): C, 50.97, 50.92; H, 5.83, 5.81; Cl, 29.97, 30.15.

EXAMPLE l3 l-4-dimethyl-1,4 cyclohexanedicarboxamide Ammonia gas is passed into a stirred solution of 0.5 part of the diacid chloride of 1,4-dimethyl-1,4-cyclohexanedicarboxylic acid and 71 parts of ethyl ether for minutes at 25 C. A white solid is filtered from the aqueous solution and warmed with 100 parts of water on a steam cone for 15 minutes. The resulting solid is filtered from the water and washed with ether. After drying in air, 0.11 part of a solid, M.P. 310 C. (uncorrected) is obtained. The product is identified as l,4-dimethyl-l,4- cyclohexanedicarboxamide by elemental analysis.

Analysis.-Calcd. for C H O N (percent): C, 60.6; H, 9.09; N, 14.14. Found (percent): C, 59.25, 59.30; H, 8.95, 9.11; N, 13.87, 14.03.

EXAMPLE 14 If 1,4-dimethyl-1,4-cyclohexanedicarboxamide is contacted with thionyl chloride at a temperature of about 100 C., 1,4-dimethyl-1,4-cyclohexanedinitrile is obtained.

EXAMPLE 15 If, l,4-dimethyl-1,4-cyclohexanedinitrile is contacted with hydrogen in the presence of Raney nickel catalyst and ethyl ether solvent, 1,4-dimethyl-1,4-cyclohexanedimethylamine is obtained.

EXAMPLE 16 Preparation of polyester from trans-1,4-dimethyl-l,4- cyclohexanedicarboxylate of 2,2-bis(hydroxyphenyl)- propane 2,2-bis(p-acetoxyphenyl)propane (15.60 parts), 10 parts of trans-1,4-dimethyl-1,4-cyclohexanedicarboxylic acid and 0.074 part of KOAc are placed in a polymer tube fitted with a nitrogen capillary tube. Acidolysis begins when the mixture is heated to 255. After 2 hrs. and 25 minutes at 255 265 C., 4.2 ml. of acetic acid has distilled from the reaction mixture. After acidolysis has continued at 287 at atmospheric pressure for another 40 minutes, the pressure is reduced to 0.07 mm. and the polymerization is completed by heating at 285- 293/0.07 for 3 hrs. The resulting polymer is identified as having the following structural formula:

CH3 OH: in The product is amorphous, melts at 255-265", is soluble in methylene chloride and has an intrinsic viscosity of 0.96. Stiff, wiry yarn ([1;]=0.67) is melt spun at 355.

Polyester having an intrinsic viscosity of 0.83 is dry spun from 72/25 Triclene/trifluoroacetic acid (33.5% solids, wt./vol.) to 12 d.p.f. yarn.

EXAMPLE 17 Preparation of polyester from trans-1,4-dimethyl-L4- cyclohexanedicarboxylic acid and hydroquinone 10 ylene chloride (25/75) and has a crystalline X-ray diffraction pattern. Tenacious fibers can be drawn from the melt. The structural formula of the product is:

Polymers of cis/trans (15/ )-1,4-dimethyl-l,4-cyclohexanedicarboxylic acid and 1,2-bis(p-hydroxyphenyl) ethane A polymer tube is charged with 14.90 parts 1,2-bis- (p-acetoxyphenyl)ethane, 10.00 parts of 15/85 cis/trans 1,4-dimethyl-1,4-cyclohexanedicarboxylic acid and 0.074 part of potassium acetate and the tube fitted with a capillary force supplying nitrogen. The mixture is heated to 255 whereupon acetic acid begins to evolve. After 1 hr. at 252-256 the temperature is raised to 260-273 for 1% hours. The pressure in the tube is then reduced and the polymerization completed by heating at 285- 290/0.5 mm. mercury for 3 hours. The resulting polymer is insoluble in 25/ 75 trifluoroacetic acid/methylene chloride, has a melting point of 308 and has a crystalline X-ray diffraction pattern. Tenacious fibers can be drawn from the melt. The structural formula of the product is identified as:

Preparation of polyester from 1,4-dimethyl-1,4-bis(hydroxymethyDcyclohexane and terephthalic acid A polymer tube is charged with 12.04 grams of 15/85 cis/trans 1,4 dimethyl-1,4-bis (hydroxymethyl)cyclohexane and 11.64 grams dimethyl terephthalate. The mixture is heated until melted and then 10 drops of catalyst solution consisting of 12% NaHTi(OBu) in n-butyl alcohol is added, and a capillary inserted through which nitrogen is bubbled. Ester interchange is accomplished by consequently heating for M2 hour at 220 C., /2 hour at 230 C., 1 hour at 255 C., and finally V2 hour at 280 C. Then the pressure in the tube is reduced to 0.8 mm. mercury and polymerization continued for 20 hours at 280-285 C. The polymer produced melts at 230 C., has an intrinsic viscosity of 0.92 and a carboxyl value of 0. The second order transition temperature, Tg, as determined by differential thermal analysis, is about C.

The structural formula of the recurring unit of the product is identified as:

WR /WR 40 c. Wet 69/47 TR /TR 40 C. wet 93/78 TSR, percent 74 Tg, the second order transition temperature, is defined herein as the temperature at which a discontinuity occurs in the curve of a first derivative thermodynamic quantity with temperature. It is correlated with yield temperature and polymer fluidity and can be observed from a plot of density, specific volume, specific heat,

11 sonic modulus or index of refraction against temperature. A convenient method for determining Tg for a given sample of polymer is given by Pace in his US. Pat. 2,556,295 (col. 3, line 24, to col. 4, line 19).

from the same stress-strain curve employed to measure the tensile recovery at x percent elongation. WR is calculated as the percentage ratio of the area under the controlled relaxation curve to the area under the Values of tensile strain recovery (TSR) for a filament stretching curve. In the examples, WR and WR refer to are an indication of the wash-wear performance to be work recovery from 3% and 5% elongation, respectively. expected from garments prepared from such filaments.

The TSR of a filament is determined by mounting a EXAMPLE 20 inch length of the filament on a tensile tester with record Preparatlon of polyester from y 1 ing chart (commercially available from the Instron Engiy y y )ey a a t s- ,4- y neering Corporation, Quincy, Mass.) and also equipped 1,4-cyclohexanedlcarboxyllc acid with a circulating water bath which can be raised and A polymer tube is charged with 8.60 grams of trans lowered. The water bath, maintained at 40 C., is raised l4 dimethyl l4 bis(hydroxymethyl)cyclohexane and 912 to Immerse fi i- After fi1fm 1ent has 15 grams of trans-1,4-dimethyl-1,4-bis (carbomethoxy)cyclo mersed for 2 minutes wlthout tension 1t ls stretched, n the henna The mixture is melted and then to the tube is water bath at an elongation rate of 1 lnch per minute. added 10 drops of a 12% Solution of NaHTi(OBu)8 in Upon reaching the desired total elongation, the sample 18 n buty1 alcohoh Ester interchange is accomplished by held at constant length for an additional 2 minutes and heating 1 hour at C ,1 hour at C" 1 hour the water bath is removed. The load on the filament s 20 at and v1 hour at 0 0 Pressure in the tube is then reduced to a value of 0.042 g.p.d. and the filament 1S then reduced and polymerization continued by heating 5 allowed to retract. Percent recovery is calculated from hours at 2804850 with a pressure of 007 mm of the formula: mercury and then heating 15 hours at 280-285 C. with a Units of retraction 100 pressure of 1.0 mm. mercury. The polymer produced has f elongation an intrinsic viscosity of 0.78, a PMT of 240 0. and a free carboxyl content of 0.0.

This procedure is carried out for elongations of 0.5, 1, The structural formula of the recurring unit of the 2 and 3%, and a graph is prepared by plotting the percent polymer is identified as: recovery against total elongation in the range 0-3%. CH 0 CH3 TSR values are average percent recovery values from I g the range 0-3% elongation which may be determined T C O from the graph by usual graphical averaging procedures. OH; on, d J

Filaments having TSR values of 60% are considered a to have good tensile recovery, while filaments exhibiting The Polymer 15 Q at 275-285 and then TSR values of 70% and above are considered quite drawn X at 100 to glYeayam havmgatenaqltrof Supcrion 2.0 g.p.d., a break elongation of 31% and an initial TR tensile recovery from x percent elongation, is a modulus of 28 a measure of the extent to which a fiber or a yarn recovers mock fimshmg and heat's?tt1ng, at 180 f its original length after being stretched, as determined yam 15 tested for recovery Propertles Wlth the followlng from a stress-strain curve. =In this test, the sample is 40 results: stretched at the rate of 10% of its test length per mi l fi WR /WR 40 C. wet 62/59 until it has reached approximately x perce t e g TR /TR 40 C. wet 89/85 after which it is held at this elongation for 30 seconds TSR, percent 61 and then allowed to retract at a controlled rate of 10% per minute, based on its original test length. The extension EXAMPLES 21*37 during the elongation and the recovery during retraction Following procedures similar to that of Example 19, are measured along the elongation axis. TR is then a series of polyesters are prepared from 1,4-dimethylcalculated as the percentage ratio of the amount of fiber L l-bis(hydroxymethyl)cyclohexane and a variety of diretraction to the amount of its elongation. In the exacids. The polymers are tested for melting point and l TR d TR r f to t ile recovery fro 3% 00 intrinsic viscosity with the results shown in Table 2. and 5% elongation, respectively. Several of the polymers are tested for second order tran- WR work recovery from y percent elongation, is a S1t1011 temperature Others are mel -Spun into measure of the freedom from permanent realignment of yarn and tested for restrained recovery VCI'SLIS extension the polymer molecule following stretching of the fiber Values of 8 and TSR are also recorded in the or yarn. The ratio of the work done by the polymer table.

TABLE 2 Biol elsltrans PMT, s; TSR, Tg, Example ratio Acid O. percent C.

35/65 Bibenzoicacid 300 1.15 35/65 Bis-kcarboxyphenyl sulfoxide 234 0.61 15/85 .do. 295 0. 55 0/100 Bis-4-earboxyphenylether- 225 0.67 35/65 Terephthalic acid 185 0.82 0 100 do... 299 0.40 35/65 Naphthalene-2,6-dicarboxylie acid 276 0.81 15/85 do"- 260 0.73 0/100 1,2-bis(tearboxyphenyDethane 250 0.95 0/100 1,2-bis(4-earboxypheuoxy)ethane 205 0.97 0/100 1, l-bis(4-earboxyphenoxy)butane 210 1.17 15/85 Bis(Harboxyphenoxy) cis-p-hexahydroxylylene. 230 0, 76 15/85 Bis(4-carboxyphenoxy)-trans-p-hexahydroxylylene 290 0.77 35/65 1,4-bieyelo[2.2.2]octane dicarboxylicacid 215 0.61 15/85 do 270 0.30 0 100 ..do. 305 0.23 0/100 Terephthalic acid/isophthalic acid (85/15) 192 0.69

molecule in attempting to return to their original align- EXAMPLE 38 ment following stretching to a predetermined elongation to the work done on the sample during stretching is termed To illustrate hydrolytic stability, three of the polymers described above are subjected to a test in which the loss the work recovery. The work recovery is determined in weight is measured after boiling for 3 hours in 3% sodium hydroxide solution. The results are shown in the following table, which also includes the value obtained for polyethylene terephthalate in the same test. The superior performance of the polyesters of this invention is obvious from an inspection of the data.

The polyester of Example 30 is melted and spun into yarn at a temperature of 262 C. Remarkable thermal stability is shown by the fact that the polymer suffers no detectible loss in intrinsic viscosity during spinning and, when analyzed for free carboxyl groups, shows carboxyl values of 0.0 for both polymer and yarn.

EXAMPLE 40 Polyamide of 1,4-dimethyl-1,4-cyclohexanedicarboxylic acid and hexamethylenediamine A stoichiometrically balanced nylon salt is prepared from hexamethylenediamine and l,4-dimethyl-l,4-cyclohexanedicarboxylic acid, sealed in a polymer tube and heated to a temperature of 280 C. for 3 hours. The product at this point has an inherent viscosity of 0.28, measured in sulfuric acid. The product is further polymerized in the solid phase for 15 hours at a temperature of 285 C. in an atmosphere of steam. The final product has an inherent viscosity of 1.03, measured in sulfuric acid, and a melting point of 372 C. by differential thermal analysis.

The polymeric product is then melt-spun using a press spinner at 390 C. to give a yarn which has an inherent viscosity (sulfuric acid) of 0.84 and which can be drawn 5.3x at a temperature of 210 C.

To illustrate stability, a polyamide prepared as above, except not exactly stoichiometrically balanced, is heated in a steam atmosphere at 325 C. for a period of 8 hours and found to sutfer no change in inherent viscosity. The polymer is then heated under nitrogen for 55 hours at 255 C. and gives no sign of gelation. Further heating at 285 C. under nitrogen for 24 hours still gives no sign of gelation. This is remarkable when it is realized that a polyamide prepared from hexamethylenediamine and unsubstituted 1,4-cyclohexanedicarboxylic acid will show extensive gelation when heated under these conditions.

The inherent viscosity is equal to where c is 0.5 g. polymer per 100 ml. solvent.

EXAMPLE 41 Polyurethane from hexamethylene diisocyanate and DMeHPXG Hexamethylene diisocyanate, 5.04 g., and 5.16 g. 1,4- dimethy1-1,4-bis(hydroxymethyl)cyclohexane are reacted in 150 cc. of refluxing, stirred chlorobenzene. After hours, the reaction mixture is evaporated to dryness and the residue dissolved in methylene chloride. Water is added and the methylene chloride driven off by boiling the water. On cooling the water, a solid polyurethane product is obtained having a melting point of 116 C., [1;]'=0.31.

EXAMPLE 42 Polyurethane from hexamethylene bis(chloroformate) and 1,4-dimethyl-l,4-bis (amino methyl) cyclohexane Equimolar proportions of hexamethylene bis(chloroformate) in chloroform and 1,4-dimethyl-1,4-bis(amino methyl)cyclohexane are reacted in water in the presence of 1% excess NaOH under high speed stirring conditions in the presence of sodium laurylsulfate detergent. The resulting product is collected, dried, and is identified as a polyurethane.

I claim:

1. A filmor fiber-forming polyester consisting essentially of recurring units represented by the formula:

wherein R is a lower alkyl radical having one to four carbon atoms and G is a divalent organic radical obtained by removing the hydroxyl groups from an organic diol selected from the class consisting of bis(hydroxymethylcyclohexyl), bis(hydroxymethylcyclohexyl) alkanes, ethylene glycol, propylene glycol, butylene glycol, 2,2-dimethyl propylene glycol, 2,2,3,3,4,4-hexafluoro 1,5 pentanediol, hexamethylene glycol, decamethylene glycol, diethylene glycol, ethylene-dioxydiglycol, heXahydro-p-xylylem glycol, quinitol, 1,4-bis(4-hydroxymethylcyclohexyl)cyclohexane, 1,4-bis(3-hydroxypropyl)benzene, 2,6-bis(2hydroxyethyl)naphthalene, 1,4-bis(2 hydroxyethoxy)benzene, hydroquinone, 4,4-dihydroxybiphenyl, 2,2 bis(4- hydroxyphenyl) propane, 1,2-bis (4-hydroxyphenyl) ethane, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl) ethane and 1,2-bis(4-hydroxyphenoxy)ethane.

2. A polyester as defined in claim 1 consisting essentially of recurring structural units represented by the formula:

3. A polyester as defined in claim 1 consisting essentially of recurring structural units represented by the formula:

4. A polyester as defined in claim 1 consisting essentially of recurring structural units represented by the formula:

References Cited UNITED STATES PATENTS 12/1965 Macon 26047 2/ 1972 Schreyer 260617 R OTHER REFERENCES Kundu et al.: J. Chem. Soc. (1965), pp. 2749-2763.

LESTER L. LEE, Primary Examiner US. Cl. X.R. 

